I bought a 1998 Ford E-350 6.8 Litre V10 with 200,000 miles. Its a 17 ft Uhaul with Arizona plates. The body is in great condition 8/10. The v10 runs like a well tuned race car. No spit, no sputter. Engine doesn"t move. The only thing I am ancie about is changing the plugs. Have no idea when it was done or how long its been. I would like to know if spraying WD-40 down the plug wholes a couple of times before I take the leap of faith of changing them is a good idea or maybe someone knows of a better product/betterway. An ounce of prevention is worth a pound of cure. Just need to get through this first step. Any help is greatly apppreciated.

 

I never spray anything down in the hole but my plug change intervals are half the miles of what Ford recommends.

Change plugs on a cold engine and remove the plugs with a ratchet that allow you to get a good feel for resistance. If the plugs are turning out hard obviously you have an issue there and can do damage. If coming out hard letting some penetrating oil soak down in will help.

That said I have changed plugs on vehicles with aluminum heads where the plugs squealed like a pig the whole way out but did not damage the threads. The aluminum used to make heads usually have a decent amount of silicon so they are not that soft.

This is the set I use and work very well for doing plugs on the modulars as well as other vehicles.

http://www.gearwrench.com/auto-specialty/service-kits/gearwrench-41740d-3-pc-magnetic-swivel-spark-plug-set.html

For plugs I primarily use the Motorcraft single Platinums however the Autolite Iridiums have done well in my dads V10 for th elast 30k or so. So I will go with the iridiums in mine next change.

 

Thanks so much. Your info is extremely helpful. That wrench set is great and I will be ordering it soon. Thx

 

I just changed mine at 112k miles. Didn't use any penetrating oil to get the plugs out, and they came out fairly easy.

one thing to remember, use an air gun and blow out around each plug first. There seems to be a bunch of crap down in each recess where the plugs sit. blow this stuff out first so it doesn't get down in the cylinders when you take the plugs out.

 

When I bought my V-10 from my nephew.
He hadn't ever changed the plugs as long as he'd had it.
About 3 years. Not sure when they were changed if ever.
I had to clean out the holes with an air nozzle and a screwdriver.
Took me about 8 hours to change all 10